feat: implement local/opencode script (#1481)

Why: local/opencode was listed as 'missing' in manifest.json — users
could not run OpenCode on their local machine via spawn.

- Add local/opencode.sh following the same pattern as other local scripts
  (sources lib/common.sh, uses opencode_install_cmd from shared/common.sh,
  injects OPENROUTER_API_KEY via generate_env_config)
- Update manifest.json matrix entry from 'missing' to 'implemented'

Agent: team-lead

Co-authored-by: B <6723574+louisgv@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

local/opencode.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+set -eo pipefail
+
+# Source common functions - try local file first, fall back to remote
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)"
+if [[ -f "${SCRIPT_DIR}/lib/common.sh" ]]; then
+    source "${SCRIPT_DIR}/lib/common.sh"
+else
+    eval "$(curl -fsSL https://raw.githubusercontent.com/OpenRouterTeam/spawn/main/local/lib/common.sh)"
+fi
+
+log_info "OpenCode on local machine"
+echo ""
+
+agent_install() {
+    install_agent "OpenCode" "$(opencode_install_cmd)" cloud_run
+}
+
+agent_env_vars() {
+    generate_env_config \
+        "OPENROUTER_API_KEY=${OPENROUTER_API_KEY}"
+}
+
+agent_launch_cmd() {
+    echo 'source ~/.zshrc 2>/dev/null; opencode'
+}
+
+spawn_agent "OpenCode"

manifest.json

@@ -232,7 +232,7 @@
     "local/openclaw": "implemented",
     "local/zeroclaw": "implemented",
     "local/codex": "implemented",
-    "local/opencode": "missing",
+    "local/opencode": "implemented",
     "local/kilocode": "implemented",
     "hetzner/claude": "implemented",
     "hetzner/openclaw": "implemented",